Coverking Custom Fit Car Cover for Select BMW Z4 Models - Silverguard (Silver) Made from a unique water-resistant, 300 dernier polyester with special reflective properties to prevent sun damage to your vehicle Strong heavy weave will not rip or tear but is ideal for mild temperate climates (not intended for extreme weather) Manufactured using unique double-stitching and waxed thread technology as well as the fewest seams possible to reduce leaks and provide greater durability Tailor-made to the exact specifications of your vehicle's year, make, model, and configuration options Neoprene elastic tensioners sewn in the front and rear keep cover in place while the additional security grommets on outdoor covers allow you to utilize an optional lock and cable kit